Initialize viewport on given painter
allow for release and debug specific compile flags using cmake generator expression
Merge branch 'master' into renew-project-structure
Move directory traversal back to public API
Merge branch 'master' into navigation

Conflicts:
	source/examples/viewer-qt/CMakeLists.txt
	source/gloperate/CMakeLists.txt
Merge branch 'navigation' of github.com:hpicgs/gloperate into navigation